Hydraulic pump



Feb. 10, 1942. J. a. HAwLEY, JR

HYDRAULIC PUMP Filed March 16, 193B 6 Sheets-Sheet 1 Im/@nier f///fvE//fm/Erdm Morney 6 Sheets-Sheet 2 Las;

Feb. l0, 1942. J. a. HAwLEY, JR

HYDRAULIC PUMP Filed March 16, 1938 Feb. 10, 1942. J, B HAWLEY,V JR 2,272,771

HYDRAULIC PUMP Filed March 6, 1958 6 Sheets-Sheet 5 Feb. I0, 1942.

J. B. HAWLEY, JR

HYDRAULIC PUMP Filed March 16, 1938 6 Sheets-Sheet 4 In zndr dof/NZ rmer/1r ZHKZ HYDRAULIC PUMP Filed March 16, 1938 6 Sheets-Sheet 5 J. B. HAWLEY. JR

Feb. l0, 1942.

Feb. l0, 1942. J. s. HAwLEY, JR

HYDRAULIC IUMP Filed March' 16,` 1938 6 Sheets-Sheet 6 Patented Feb. 10, 1942 UNITED STATES PATENT OFFICE `HYDRAULIC PUMP John B. Hawley, Jr., Minneapolis, Minn. Application March 16. 1988, Serial No. 196,225

lclalms.

This invention relates to a iluid pump. motor or hydraulic transmission device and particularly to such a device of the kind known as the rotating cylinder barrel in which pistons reciprocate'. these pistons being movable by a rotating awash plate rotating about the axis of the cylinder barrel but being given a wobble motion by a tilting plate which can be tilted at various angles to the axis oi said cylinder barrel.

It is an object of this invention to provide such a device comprising a novel form of piston and specifically a piston having an outer surface of hard bronze welded onto steel.

It is a further object oi' the invention to provide such a device having a tilting plate together with simple, novel and emcient means for varying the inclination of s'aid tilting plate.

It is another object of the invention to provide a novel form of indicator showing the inclination of the tilting plate and one which will be normally covered and sealed.

It is still another object oi' the invention to provide a novel structure of lubricating the valve plate engaged by the cylinder barrel.

It is still further an object of the invention to provide a novel construction oi discharge and inlet pipe in combination with the pump parts.

It is also an object o! the invention to provide a novel structure of valve plate and particularly to provide a novel surface for the valve plate engaged by the cylinder barrel.

It is further an object of the invention to provide a novel construction of frame or casing for the pump and a novel form of supporting means for said casing. l

These and other objects and advantages of the invention will be fully set forth in the iollowing description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in which:

Fig. l is a perspective view of the device, some parts being broken away and others shown in vertical section;

Fig. 2 is a view partly in side elevation of the device and partly in central vertical longitudinal section Fig. 3 is a horizontal section taken substantially on the plane of the axis of the inlet and discharge conduits and of the Pcentral driving 4 shaft:

Fig. 4 is a partial view in side elevation showing the indicator cover with a portion of the cover being broken away to show the indicator;

awash plate type. Such a device comprises a` Fig. 5 is a view in vertical section taken substantially on line 5-5 of Fig. 6 as indicated by the arrows;

Fig. 6 is a partial vertical section taken substantially on line I-B of Fig. 3 as indicated by the arrow;

Fig. 7 is a vertical section taken substantially on line 'I-l of Fig. 3, haii oi' said view looking in one direction and haii' thereof looking in the other direction;

l Fig. 8 is a partial horizontal section taken on line l-I or Fig. 'l as indicated by the arrows; and shown on an enlarged scale;

Fig. 9 is a partial section taken on line 9--9 of Fig. 7 as indicated by the arrows:

Fig. 1071s a view partly in side elevation and` partly in vertical section showing the structure oi' the inlet and discharge conduits:

Fig.i1isaviewsimilartoFig.6showinga modiiication;

Fig. l2 is a view as seen from line Il-IZ of Fig. 1l looking inthe direction of the arrows; and

Fig. 13 is a view similar toFig. 6 showing a modidcation.

Referring to the drawings a device such as referred to above is shown comprising a casing section Il. As illustrated, this section is made oi' box-like form rectangular in vertical cross section. A front end plate I6 is secured to one end of casing I5. the same ntting tightly thereagainst and having therewith a rabbeted joint comprising a ledge and shoulder indicated at lia. A rear end plate or valve plate I] is provided iitting against the other end of casing i5 and also havingtherewith a rabbeted or oilset joint as indicated at Ila. Angle members or brackets II have vertical flanges disposed against the outer sides ot plates lli and I7 and have horizontal anges ita constituting feet or supports for the casing, the same having holes IIb therethrough which may receive securing bolts. Long screws I9 extend through section I5 and the plates Il and I7 as well as brackets IB, the same being disposed adjacent the corners oi the casing and being threaded at their ends to receive the securing nuts 2li. Bolts I! therefore secure said has an inner short iiange 22a set into the outer end o! plate IB and is recessed to carry a ball bearing 23. Plate Il is recessed at its inner side to receive a ball bearing casing 24 and said plate also has a thrust plate 25 set thereinto. A driving shaft 26 is Journalled in the bearings 23 and 24, the same having its inner end engaging plate 25 and having a shoulder engaging the inner side of bearing 23. A cylinder barrel 21 surrounds shaft 28 adjacent its inner end and is secured thereto by the oppositely disposed keys 28, said keys being shown as having cylindrical shanks or projections fitting in similarly shaped holes in shaft 26. Said keys extend into keyways 21a in cylinder barrel 21. Shaft 26 has a threaded portion 26a adjacent its inner end receiving a collar 29 and a nut 30 engaging said collar. Collar 29 engages a shoulder on said shaft adjacent said threaded portion. Shaft 28 has a 'yoke 2Gb formed thereon at the-inner side of barrel 21 and a coiled compression spring 3| surrounds shaft 26 bearing at one end against yoke 26h and at its other endagainst barrel 21, said spring being partly disposed in the recess in barrel 21. Spring 3| acts to press cylinder barrel 21 against the fiat face of the valve plate I1. Barrel 21 has a flat face engaging said valve plate and has formed therein a plurality of cylinders 21h, the same being shown as nine in number and said cylinders having openings 21e at their inner ends forming inlet and discharge openings which openings are of the form and disposition shown in Fig. 7. A swash plate 22 surrounds shaft 28 at yoke portion 26h. Said yoke portion has bores at opposite sides receiving bushings 33 in which are ,iournalled the ends of a main shaft pin 34. The central partof shaft pin 34 extends through a trunnion block 25 disposed within yoke 2Gb and having trunnions 35a at opposite ends projecting at right angles to pin 34. Trunnions 35a are received in bushings 36, said bushings or bearings 36 in turn received in trunnion bearing blocks 31 which are received in swash plate, 32 and locked therein. Swash plate 32 is thus rotated by shaft 26. Cylinder barrel 21 has a piston 38 in each of its cylinders, said piston having a bore in the inner end of which is disposed a ring socket 39 having a semi-spherical recess therein adapted to receive the end of a ball as formed on one end of aconnecting rod 4II. A connecting rod end bushing engages the outer end of a socket 28 also having a surface fitting part of the other half of the ball 40a and held in place by a flanged hollow nut 42 threaded into the bore of piston 28, the ange thereof engaging the end of said piston. While pistons 38 might `be variously made, in practice it has been found highly eilicient to have them made of steel, the cylindrical bearing portions of the pistons being coated with .a coating 30a of hard bronze welded'thereon.

Connecting rod 4II has a ball 40h at its other end and swash plate 22 is provided with a plurality of sockets equal in number to and aligned with the cylinders in barrel 21. Each of said sockets has disposed therein a ring socket 43 receiving the outer end of ball 40h. A bushing 44 engages the member 43 and also has a partly spherical surface engaging ball 4Gb. A nut 45 is threaded into swash plate 32 and engages.

member 44, the same being hollow to accommodate connecting rod 40. Some locking means, not shown, will be provided for locking nuts 42 and 45 in place. Swash plate 32 is recessed at its outer side to receive a hard bearing plate 46. A tilting plate 41 of ball-like form surrounds shaft 26 and has a large central opening through which said shaft passes.

large trunnions at either side thereof which are journalled in roller bearings 48. The bearings 48 are carried in bearing brackets 48 which are secured to end plates IB by the headed bolts 50 which pass through said4 brackets at the sides on plate 41 and secured therein by a tapered pin Plate 41 has rather 75 52. Fork 5| has flat surfaces at the inner sides of its arms between which is disposed a block 53. Block 53 is centrally bored to receive the roller bearings 54 and a pin 65 extends centrally through bearings 54 and has its ends disposed in the arms of fork 5I. Block B3 has flat top and bottom sides and these are engaged by bearing sleeves 5B mounted on roller bearings 51 into which bearings extend the bearing shafts 58. Shafts 5B are secured in the sides of a yoke 59a formed on the lower end of a vertically ex` tending control shaft 58. The yoke 59a has secured thereto a key member 60 fitting in a keyway in the end plate IB and extending from the bore isb formed in said end plate and in which the yoke or cage 59a slides, the latter having outer cylindrical surfaces as shown in Fig. 3. Key 60 is secured to portion 59a adjacent its top` and bottom by the pins 6I. Shaft 59 and the portion 59a are thus guided for vertical nonrotative movement. Shaft 59 passes through the flanged bushing 62 fitted into a cover member 63 closing the outer end of bore 16h and being bored to accommodate the packing material 64 pressed therein and about shaft 59 by the gland 65. A stop block t6 has a reduced threaded ystem secured in plate I6 at the bottom of bore lib and limits the downward movement of shaft 5l. It will be seen that by raising and lowering shaft iii that block 52 will be raised and lowered and this in turn will move plate 41 about the axis of its trunnions. Block 53 can move parallel to the axis of shaft 2B but can have no rotative movement. Plate 41 is recessed to receive a bearing plate 01 and roller bearings 6I are disposed between plate 61 and plate 46. Plate 46 at its outer edge also engages roller bearings 68 so that swash plate l2 rotates against both bearings 6l and 69.

casing section is 1s provided wan a. cyundncar opening lia and a reduced cylindrical portion of a bracket 10 fits' into said opening. bracket 1I being secured to the side of section il by a plurality of circumferentially spaced screws 1l having their heads countersunk into member 110. The adjacent trunnion of tilting plate 41 is recessed to receive the flange 12a of a member 12, said ilangefbeing secured to said trunnion by the circumferentlally spaced bolts 1L Member 12 has a cylindrical portion projecting outwardly from flange 12a and this extends through a cylindrical central opening in bracket 10, the same projecting a short distance beyond the outer surface of bracket 10. An indicator pointer 14 is provided with a hub set into the outer end of member 12 and said hub and pointer are secured to member 12 by the headed bolt 15 engaging a washer 16. A pin 11 also extends through pointer 14 into `member 12. Pointer 14 cooperates with graduations 14a formed on the face of member 10. Packing 1l surrounds member 12 within member 10 and is carried in a casing 1l.

The pointer il is covered and enclosed by cover plate II secured to member 1l by the circumfer-v entially spaced headed screws Il. a gasket l2 being placed between said members to insure a tight seal.

As stated, end plate Il forms a valve plate and is provided with a bronze surface I'Ib welded onto said plate which is made of Invar` steel. This steel used contains about 57 percent nickel and has one-twentyflfth the coemcient of expansion of regular steel. Outside of bearing Il the face ofthe valve plate is tightly engaged by the outer fiat face of barrel 21. Valve plate Il has an annular bearing surface llc and this is provided with diametrlcally Opposite arcuate slots I'Id, one of which forms an lmet port and the other of which forms an outlet port. 'Ihese slots extend through plate il and communicate with the discharge openings Ile. Small grooves I'ldd extend from each end of slots IId for a short distance. Said valve plate has another annular bearing surface Il! outward of ports Ild and this bearing surface has the grooves Ilg at either side thereof. A series ofholes IIh are formed in bearing surface I 1f located substantially centrally thereof and in circumferentially spaced relation. VA passage lli extends from each side of and substantially at the bottom of each opening IIh into the grooves llc. Oil can thus Dass or be forced through the passages lli and into the holes I'Ih so that a film of oil will always be provided on the bearing surface llf. A bridge of metal |11 extends across each slot i 1d substantially at the center thereof, said bridge being of comparatively narrow width and of comparatively small depth, the same having its top surface disposed below bearing surface llc, 'I'he outer side of plate Il is provided with a pair of parallel bores in alignment with the discharge ,openings lle and rings l! are disposed in the bottom of said bores against the shoulder formed therein.` said rings having inwardly extending flanges Bla. Coupling members Il have cylindrical pipe portions extending into reduced extensions of the bores in plate Il, said portions each having an annular groove Ila. formed therein in which the flanges Ila of the rings l! extend. Rings II must of course, be in two parts. Packing 81 is disposed in said bores engaging the rings Il at its inner ends and being engaged at its outer end by the glands Il, said packing thus being tightly pressed about the pipe portions oi' members Il. Glands I8 as usual have flanges through which extend the headed bolts Il threaded into the end of plate l1. The inlet and discharge conduits Il are suitably connected to members 88. As shown in Fig. l packing material 9| is disposed in member 2! about shaft Il, said material being engaged by the cylindrical portion of a packing gland l! extending into the bore of member 22. Gland Il has a flange through which pass the bolts 92a threaded into member 22 and material 0I is thus compressed about shaft 26. The outer end of shaft 26 is shown as having a reduced portion threaded with a keyway 2Bc adapted to receive a suitable driving member. Casing II is shown as having an opening ltd in its top about which is secured a member 93 having an annular flange a entering an annular groove Ile in casing Il. A gasket may be placed beneath ange no. Member Il is shown as interiorly threaded and is provided to receive a connection to an expansion tank which may be disposed above casing Il.

In Fig. 11 a lmodiiied form of an adjusting means for tilting plate Il is shown similar to plate 41. In this form said Plate is Provided with a reduced portion a having nat surfaces and flexible metal bands or ribbons Il and are secured respectively to said surfaces by the bolts a and pins Il. A plunger lla formed on an adjusting shaft 9| is of cylindrical form at its top and bottom and nts in bore I lb being slidable therein. Said plunger is kept from rotation by 'having a keyway in its outer side in which is disposed the key Il secured to plate il. Plunger lla is cut away at its inner side to have a flat surface substantially in the plane of its axis and the other ends of bandsv l and il are secured respectively to the upper and lower portions of this surface by the bolts Ill and pins IDI; The lower end of bore IIb is closed by a ilanged plug |02 and the upper end of said bore is closed by a hanged plug |03. Plug lll is bored to have a anged bushing |04 at its inner portion surroundingshaft I and packing lill surrounds said shaft in the bore of member |08 and engages bushing lll. A gland I surrounds shaft I and extends into the bore in member IDI to engage and compress the packing III about shaft Il. Shaft ll is shown as having a reduced threaded portion IIb at its upper end which will receive some suitable means for moving said shaft. It will be seen that when shaft Il is moved vertically that plate 94 will be rotated about its trunnions in a counter-clockwise direction. The bands I5 and II move over the convex or semicylindrical outer portion of projection Ila. When shaft Il is moved downwardly plate Il will be tilted in a clockwise direction about its trunnions.

In Fig. 13 s further modification is shown in which the tilting plate ill similar to plate l1 is provided with a lateral projection Illa in the form of a fork between the arms of which is secured a member III having spaced annular ribs or projections Illa thereon. A plug Il! closes the lower end of bore IIb and at its inner end is provided with a thrust tapered roller bearing Ill. A nange plug HI closes the upper end of bore IGb and also carries at its inner end a thrust tapered roller bearing III. An adjusting shaft IIS extends through bearings IIS and Ill and is provided with shoulders engaging the adjacent sides of said bearings. Shaft III is provided adjacent member III with a worm or helical gear formation Ilia. Member H4 is bored to receive a flange bushing Ill surrounding shaft i Il. Packing material Ill is disposed in the upper and enlarged end of the bore in member III and is engaged by a gland H9 having a portion extending into said bore. Packing material III is thus compressed about the shaft Ill. Shaft I Il is provided at its upper end with a reduced threaded portion illb adapted to receive some means by which said shaft will be rotated.

It will be seen that when shaft III is rotated that the member HI will be traversed along the gear or worm portion Ilia and member or plate H0 will be rotated in a clockwise orl counterclockwise direction depending upon the direction of rotation of shaft lli. 'The parts are held firmly and securely in position and no play is permitted in said parts due to the arrangement of the bearings lil and IIB.

ply of oil or fluid to be pumped. The other conduit 9B will then form the discharge conduit. Plate 41 will be tilted to the desired angle by upward movement or shaft 59. Such upward movement as already stated, moves block il and this swings plate 41. The stroke of the pistons 3B is determined by the degree of inclination of plate 41. With plate 41 so inclined swash plate 32 is rotated by shaft 28 through the trunnion block and when the roller bearings i8 approach the side of plate 41 nearest the cylinder barrel, said bearings and plate will be moved toward the barrel and through the connecting rods pistons 38 will likewise be moved. AS the bearings 6B approach the side o! plate 41 farthest from the barrel 21 the pistons will be moved outwardly of the cylinders and barrel 21, The liquid entering the inlet pipe 80 will pass through members B6, inlet members I1e, the port I1d and through the opening 21e into the cylinders in barrel 21. Liquid is thus drawn into the cylinders as the pistons move away from barrel 21. As the barrel 21 and swash plate 32 rotate, the cylinder with the liquid therein will move into registry with the discharge port I1d andsthe pistons are then moved into the cylinder and the liquid is discharged throuh the openingsV 21o and discharge openings I1e into the other member 86 and the discharge conduit 90. Barrel 21 has its iiat face tightly engaging the bearing surfaces on valve plate I1 and by the construction of the holes |11: and passages I1i a film of oil is maintained on these surfaces giving perfect lubrication. Bridge IU strengthens the valve .plate and the port I1d. It will be seen that some motion ci the inlet and discharge conduits 90 longitudinally thereof is possible without placing much strain or twisting stress upon valve I1. This is very important as the surfaceof the valve plate must be kept in close contact with the end of the cylinder barrel. The elimination of the stresses placed on the valve plate by the inlet and discharge pipes is thus a great improvement. There is a considerable diierence in temperature of the incoming and outgoing oil due to the high pressures developed in the pump and it is necessary to have a valve plate which has a very low coefilcient of expansion. This problem has been solved in the present case by using a. high nickel Invar steel as above described. The pistons 3l being coated with a coating of hard bronze welded onto the steel are also very strong and durable and there is low friction between the pistons and the cylinder wall. The construction o! applicant's casing also results in a great improvement. Not only are the parts comparatively simple and easily made but it will be seen that when the plate I1 is removed that the bolts 5l holding the tilting plate trunnion bearings can then be removed. The indicator member 12 can be removed and the whole pump mechanism Including the shaft 26, swash plate 32 and the cylinder barrel can be removed through one end ci' casing section I5. It will be seen that block Il can be removed from between the bearing sleeves i6. The casing section I! is of exceedingly simple construction. A simple and eicient connecting means for the casing is also provided by the long bolts n.Il which also hold the feet brackets I8. By providing roller bearings for the trunnions of tilting plate 41 this plate may be quite easily adjusted. There is a considerably impending motion or gyroscopic effect on this part and this is practically eliminated by the provision of the roller bearings. The mechanism provided for adjusting the tilting plate is very simple and highly edlcient. y No play can take place between the parts 53, 59a and the fork 5I.

The structure of the indicator comprising the pointer 14 is also novel. It is not desired to observe this with great frequency. It is sometimes desired to know when the pump is in neutral position that is when there is no inclination of plate 41. At such times the cover may be removed and the setting of the plate observed. Member 1B and packing means 18 and 19 are provided to prevent leakage of appreciable fluid while cover plate B0 is removed. At other times the indicator is entirely closed and sealed and is thus not subject to any inJury.

The cylinder casing |20 indicated only in Fig. 2, may be used disposed about the rotating parts between plates I6 and I1 and within the bolts I9 and 2| to prevent friction ci the duid in the casing with said bolts. Said casing will be made of light metal oi' comparatively small thickness.

From tne above description it will be seen that I have provided a simple, novel and greatly improved structure of a pump or nuld transmission device of the swash plate type. The device is a great improvement over the devices of the prior art. The sainel has been amply demonstrated in actual practice, has been found to be very successful and eilicient and is being commercially made.

It will be understood, of course, that various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of appiicants invention, which generally stated, consists in a device capablo of carrying out the objects above set forth, in the parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:

l. In a pump ci the swash plate type including a casing, a rotating cylinder barrel having a rigid ilat end face provided with cylinders having ports in said dat end face o! said barrel, a valve plate provided with arcuate ports cooperating with the ports of said cylinders to control the flow of the operating fluid, an annular bearing surface disposed outward radially i'rom said ports and an annular depression at each side of said bearing surface, a series of eircumierentially spaced holes formed in said bearing surface for an appreciable depth therein and small passages extending from the sides of said holes to said depressions whereby pressure duid or oil from said casing is supplied to said annular bearing surface to form a fluid nlm between said cylinder barrel and valve plate.

2. In a pump of the plate provided with arcuate ports operate with the ports of a cylinder barrel to control the now of the operating fluid, an annular bearing surface disposed outward radially from said ports and an annular groove extending about the inner side of said bearing surface. a series ci circumferentially spaced holes formed in said bearing surface for an appreciable depth therein and small passages extending from the sides of said holes to said groove whereby pressure fluid is supplied to said annular bearing surface to form a fluid tllm between said cylinder barrel and valve plate.

swash plate type, a valve 3. 'A pump or hydraulic speed transmission device ci the swash plate type having in combination, a valve plate provided with arcuate ports adapted to co-P adapted to cooperate with the ports of a cylinder barrel to control the ow of fluid, said arcuate ports cooperating with inlet and discharge passages respectively, inlet and discharge conduits extending into said passages and arranged for longitudinal movement and packing means about said inlet and discharge conduits in said valve plate whereby when great pressure is developed between said barrel and valve plate relative movement between said conduits and valve plate is permitted without placing stress on said conduits.

4. In a pump of the swash plate type. a valve plate arranged to cooperate with a cylinder barrel and provided with arcuate ports, said plate having an annular bearing surface engaged by said barrel and disposed outwardly radially from said ports and means for maintaining a lm of uid upon said hearing surface including circumferentially spaced holes within the sides of said surface and passages leading thereto from the side of said surface and disposed beneath the same so that said surface is uninterrupted by said passages.

JOHN B. HAWLEYgJR. 

